Garden Notes September 2026

In Zones 8a and 8b, September is the gateway to fall gardening. Daytime temperatures start to moderate, making it ideal for cool-season crops, fall flowers, and late-season fruit care. This month focuses on planting, transplanting, harvesting, and preparing for winter while still managing heat-tolerant summer crops.

🌞 VEGETABLE GARDEN – SEPTEMBER

🌱 Direct Sow (Fall Crops)

• Lettuce

• Spinach

• Kale

• Collards

• Mustard greens

• Arugula

• Radishes

• Beets

• Carrots

• Turnips

Tip: Sow in partial shade in hotter 8a areas to improve germination and prevent bolting.

🌿 Transplant

• Broccoli, cabbage, and cauliflower seedlings started in late August can be transplanted now.

• Leafy greens from seed trays can be moved to garden beds.

• Herbs like parsley, cilantro, and oregano transplant well.

🥬 Harvest & Maintain

• Continue harvesting heat-tolerant summer crops: tomatoes, peppers, squash, cucumbers, and beans.

• Remove declining summer crops to free space for fall plantings.

• Mulch beds to retain moisture and moderate soil temperatures.

🍓 FRUIT CARE – SEPTEMBER

• Continue harvesting late peaches, plums, blackberries, and early figs.

• Remove fallen or overripe fruit to prevent pests and disease.

• Maintain deep irrigation, especially for ripening fruit.

• Light pruning and shaping of fruit trees can be done after harvest.

🌸 FLOWERS – SEPTEMBER

Direct Sow & Plant

• Cool-season annuals: pansies, snapdragons, calendula, and sweet peas.

• Heat-tolerant perennials: zinnias, coneflowers, black-eyed susans, blanket flowers, bee balm.

Deadheading & Maintenance

• Deadhead spent flowers to extend bloom.

• Continue mulching to protect roots as temperatures fluctuate.

🐝 POLLINATOR SUPPORT

• Fall-blooming perennials like coneflowers, bee balm, and blanket flowers continue to support pollinators.

• Herbs allowed to flower (basil, oregano, thyme, cilantro) provide late-season nectar.

• Avoid insecticides during bloom periods.

✂️ PRUNING & FALL TASKS

Shrubs & Perennials

• Lightly shape shrubs before winter.

• Cut back summer perennials that are done flowering.

Roses

• Deadhead to maintain fall blooms.

• Fertilize lightly if desired.

Tomatoes & Peppers

• Continue removing lower leaves for airflow.

• Begin harvesting remaining fruit before frost.

🐛 PEST WATCH – SEPTEMBER

• Tomato hornworms

• Squash vine borers

• Aphids

• Spider mites

Inspect crops weekly and treat early to prevent damage before cooler weather slows pests.

💧 WATER & MULCH

• Maintain deep irrigation 1–2 times per week depending on rainfall.

• Mulch 2–3 inches to retain moisture and reduce soil temperature swings.

• Morning watering reduces disease risk.

🌡️ WEATHER CONTINGENCIES

Early Frost in 8a (possible late September)

• Cover tender summer crops overnight if needed.

• Move potted plants indoors or to protected areas.

Hot Early Fall

• Use partial shade for seedlings to prevent bolting.

• Mulch beds heavily to moderate soil temperature.

🗓️ September Planning

• Prepare beds for late-fall crops (spinach, kale, lettuce).

• Start planning for overwintering garlic and onions (plant late September in 8b, early October in 8a).

• Order seeds for fall/winter planting.